What's New in Hip Replacement.

Abstract

Implant Design and Related Outcomes Dual Mobility In a recent study comparing dislocation mechanisms between dual-mobility, neutral, and constrained liners using a cadaveric model and a dual fluoroscopy system, Klemt et al. observed no increase in range of motion in the dual-mobility total hip arthroplasty (THA) construct when compared with a neutral THA construct, but did observe increased provocative anterior and posterior subluxation range of motion before dislocation1. The authors suggested that this may be the mechanism for previously observed lower dislocation rates. According to a 2 to 10-year postoperative follow-up study2, surgeons considering the use of some modular dual-mobility devices may want to include the potential for increased serum metal ion levels in their decision-making. Civinini et al. reported that 29.7% of patients had ion levels above the normal range. Polyethylene In a recent radiostereometric analysis study of wear rates of 2 different polyethylene liners and 2 sizes of cobalt-chromium femoral head3, Kjærgaard et al. reported on 94 patients at a 5-year follow-up and found very low wear rates for all implants and no difference in wear rates between vitamin E polyethylene liners and conventional cross-linked polyethylene liners for both 32-mm and 36-mm heads. Patient Factors in Relation to Outcomes Young Patients According to a study utilizing the New Zealand Joint Registry4, surgeons may need an additional metric with which to counsel young patients considering THA. Nugent et al. recommended using the lifetime risk of revision. Although they found an overall, 10-year implant survival rate of 93.6%, this survival rate was lowest in the youngest age group (46 to 50 years), who had an estimated lifetime risk of a revision surgical procedure of 27.6% compared with 1.1% in those who were 90 to 95 years of age at the time of the primary surgical procedure. Most young patients who present for the first time with early hip osteoarthritis will not require THA in the following 10 years, according to van Berkel et al.5. Following 588 participants at baseline and at 2, 5, 8, and 10 years, the authors observed that patients with early, symptomatic osteoarthritis progressed to THA in only 12% of cases. During the study, Kellgren and Lawrence scores worsened and the use of pain medication increased from 43% to 50% of participants. Despite this, all Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) subscales remained constant, on average, for patients who did not undergo arthroplasty. Race and Ethnicity Using the American College of Surgeons National Surgery Quality Improvement Program, Sheth et al. identified all African American patients in the database who underwent elective, primary THA between 2011 and 2017 (11,574 patients)6. Over the study period, the authors found an increase of 109% in THAs performed in this group as well as a reduction in the prevalence of osteonecrosis, anemia, and dyspnea. There were no changes in the rates of 30-day surgical complications, readmission, reoperations, and mortality. However, there was a decrease in the rate of postoperative medical complications, especially in the incidence of postoperative myocardial infarction. In another recent study of 1,041 African American patients undergoing THA and total knee arthroplasty (TKA), Chisari et al. reported that, when controlled for demographic characteristics and medical comorbidities, there were no differences in readmission or complication rates. However, African American patients had significantly lower preoperative Hip disability and Osteoarthritis Outcome Score (HOOS) and Knee disability and Osteoarthritis Outcome Score (KOOS) values at 33.5 points compared with Caucasian patients at 45.1 points (p < 0.001)7. Preoperative Opioid Usage In a recent study, Vakharia et al. identified 42,097 Medicare patients who underwent primary THA between 2005 and 2014 and produced 2 matched cohorts of patients with and without opioid use disorder8. The authors found that patients with opioid use disorder had a higher risk of developing periprosthetic joint infections (relative risk, 1.32) and having 90-day readmissions (relative risk, 1.23) and higher 90-day costs compared with controls. Prior Hip Arthroscopy Using the Swedish Hip Arthroplasty Registry, Lindman et al. compared 135 patients who had undergone failed ipsilateral hip arthroscopy and then underwent conversion to THA with 540 age-matched controls. The authors evaluated the patient-reported outcome measures obtained with the use of multiple questionnaires9. The mean interval between the arthroscopy and the THA was 27 months. The authors reported that, at the 1-year follow-up, there were no differences in hip pain or reported satisfaction between the 2 groups. Body Mass Index (BMI) Onggo et al. recently performed a meta-analysis and systematic review of 67 studies on the topic of obesity and THA outcomes that included 581,012 obese patients and 1,609,812 non-obese patients10. The authors found that obese patients had a higher risk of dislocations, reoperations, revisions, readmissions, all complications, deep infections, and superficial infections. In a subgroup analysis of morbidly obese patients (BMI ≥40 kg/m2), the risks of all of these parameters were even greater. In addition to a higher risk of complications, Katakam et al. found that obese class-III patients (BMI >40 kg/m2) also had a higher risk of no improvement in their postoperative physical function11. The authors reported that the class-III obese patients had a nearly threefold increased risk of not achieving the minimal clinically important difference on the HOOS-Physical Function Short Form (HOOS-PS) at the 1-year follow-up. Also, the authors suggested that their data may be used for setting patient expectations. Spinal Pathology Spinal pathology is increasingly understood as a risk factor for adverse events in the population undergoing THA. In a meta-analysis of 10 articles corresponding to 9 unique observational studies totaling 1,992,366 primary THAs, Wyatt et al. identified 32,945 cases of spinal fusion12. When comparing spinal fusion with no spinal fusion, the relative risk was 2.23 (95% confidence interval [CI], 1.81 to 2.74) for dislocation in 7 studies and 2.82 (95% CI, 1.37 to 5.80) for any complication in 3 studies. The identification of patients without a history of spinal fusion but with a clinically relevant stiff lumbar spine remains a challenge. In a Level-II, diagnostic study, Innmann et al. reported that patient screening can be accomplished through a combination of physical examination and a standing lateral radiographic image of the spinopelvic complex taken using a biplanar, low-radiation-dose imaging system13. After calculating what they referred to as a “hip user index” by quantifying the percentage of sagittal hip movement compared with the overall movement between the standing and deep-flexed positions, the authors reported a sensitivity of 90% and specificity of 71% for identifying a patient with little spinal contribution to sagittal motion when the standing pelvic tilt was found to be ≥19°. Previous Hip Surgical Procedures Douglas et al. compared matched retrospective cohorts of 25,081 patients who underwent primary THA with 8,339 patients who had undergone at least 1 hip surgical procedure prior to THA14. The authors found that the patients who underwent conversion THA had significantly higher rates of complications (periprosthetic joint infections, hip dislocations, mechanical complications, and need for a revision surgical procedure within 90 days), higher transfusion rates, higher 30-day readmission rates, and higher median cost of care at 90 days compared with the patients who underwent primary THA. Surgical Factors in Relation to Outcome Surgical Approach In a study of 30,098 patients who underwent THA between 2015 and 2018 in Ontario, Canada, Pincus et al. reported finding a small but significantly increased risk of major surgical complications among 2,993 propensity score-matched patients undergoing an anterior approach (61 patients [2%]) compared with 2,993 matched patients undergoing a posterior or lateral approach (29 patients [1%]); the absolute risk difference was 1.07% (95% CI, 0.46% to 1.69%), and the hazard ratio was 2.07 (95% CI, 1.48 to 2.88)15. In a similarly large study population, Charney et al. evaluated 38,399 THAs from the Kaiser Permanente’s Total Joint Replacement Registry for the impact of the surgical approach on rates of dislocation, revision for instability, revision for periprosthetic fracture, and revision for aseptic loosening16. The authors found a slightly lower risk of dislocation in the direct anterior approach group compared with the posterior approach group (hazard ratio, 0.39 [95% CI, 0.29 to 0.53]). However, there was a higher risk of revision for aseptic loosening in the direct anterior approach group compared with the posterior approach group (hazard ratio, 2.26 [95% CI, 1.35 to 3.79]). Implant Fixation Utilizing the Norwegian Arthroplasty Register, Dale et al. evaluated the modes of fixation in primary THA and the influence of age and sex with regard to reported lower survivorship for, but increased use of, cementless THA in some populations17. Utilizing data from 2005 to 2017, the authors found a considerably higher rate of revision due to fracture and dislocation in female patients 55 to 75 years of age undergoing THA with all-uncemented designs (relative risk, 1.3 [95% CI, 1.0 to 1.7]). This was higher still in female patients older than 75 years of age (relative risk, 1.8 [95% CI, 1.2 to 2.7]). The authors recommended against using uncemented stems in THA in these patients. Cement fixation was also endorsed by multiple investigators studying outcomes for displaced intracapsular hip fractures. In a prospective, double-blinded, randomized controlled trial (RCT), Clement et al. randomized 50 patients who were >60 years of age and had an intracapsular hip fracture to THA with either an uncemented design (n = 25) or a cemented design (n = 25)18. The study was terminated early after only one-quarter of the intended enrollment was reached because of the significantly higher rate of intraoperative complications (p = 0.004) in the uncemented group (8 patients). The authors endorsed the use of cemented components in these patients. In another publication, Nantha Kumar et al. performed a systematic review and meta-analysis of 2,819 hemiarthroplasties performed for intracapsular hip fractures19. They found no difference in the risk of mortality when comparing cemented and uncemented stems, but did find that uncemented implants had a substantially higher risk of periprosthetic fracture. With regard to surgeons selectively using uncemented stems in elderly women with good bones, in a recent study of 2,635 THAs20, Hopman et al. reported 18 revisions for early periprosthetic fracture in elderly female patients. These fractures were not correlated with BMI, osteoporosis, or Dorr classification. The authors estimated that the number needed to treat to avoid 1 revision, if assuming that the patients undergoing THA with no cement would have had no fractures with cement, was 48. Complications Surgeon Age as Risk Factor The goal of identifying complication risk factors has extended to the age of the surgeon. In a study of 122,043 THAs performed by 298 surgeons, Matar et al. found that middle-aged surgeons (45 to 55 years of age) had the lowest complication rate and younger surgeons had a higher risk of composite complications, revision, and infection21. Excluding older low-volume surgeons (who also had a higher composite risk of complications), older surgeons had complications similar to those of middle-aged surgeons. Dislocation The variable rate of dislocation in the literature may be due to the difficulty in identifying all of the dislocations that are occurring, according to Hermansen et al.22. Utilizing the Danish Hip Arthroplasty Register, the authors attempted to identify the true rate of a dislocation for patients undergoing THA for osteoarthritis using what the authors described as a comprehensive, nationwide review of patient files of patients who underwent THA performed between 2010 and 2014. They reported that their final tally was 50% higher than the results from using their registry alone and cautioned that better algorithms integrating medical records may be required to use registries to monitor dislocation. According to Huerfano et al., the dislocation rate, true or otherwise, does not seem to be influenced by the surgeon’s choice of approach. In their recent meta-analysis of 25 studies (5 RCTs and 20 non-RCTs) of 7,172 THAs23, the authors compared the posterolateral approach and the direct anterior approach and found no significant differences in dislocation rates between the approaches. Subgroup analyses indicated similar results with respect to posterior soft-tissue repair (p = 0.50) and the learning curve (p = 0.77). The authors concluded that the surgical approach had no influence on dislocation rate after THA. Adverse Local Tissue Reactions Kwon et al. reported on 89 consecutive patients managed for head-neck taper junction corrosion24. They found that the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) remained useful in excluding infection. The suggested cutoffs were 57 mm/hr for ESR, with 57% sensitivity and 94% specificity, and 35 mg/L for CRP, with 93% sensitivity and 76% specificity. The authors observed no significant differences in metal ion levels between the infected and uninfected groups. Even without infection, revision for adverse local tissue reaction in the hip can be challenging because of abductor insertion necrosis. Klemt et al. reported a decreased dislocation risk for these patients when managed with a dual-mobility implant25. In their cohort of 234 such patients, no dual-mobility implant had dislocated at a mean 4-year follow-up compared with 4.1% of patients treated with a constrained liner and 15.5% treated with a conventional articulation. Technology Virtual Clinic Visits El Ashmawy et al. provided some insight into what many of our patients experienced during the COVID-19 pandemic. Reporting on 1,749 patients seen in a virtual visit between January 2017 and December 2018, the authors examined the effectiveness of and patient satisfaction with virtual visits26. They found that, for the 1-year postoperative visit and routine scheduled follow-up visits, only 7.22% of patients required a further in-person appointment. Patient satisfaction rates were similarly promising, with 89.29% reporting being satisfied or very satisfied with this mode of care. Outcome Scores Ackerman et al. examined the HOOS-12 and KOOS-12, shorter, 12-question versions of the 40-question HOOS and KOOS27. Using the Oxford Hip Scores, Oxford Knee Scores, and EuroQol-5 Dimensions-5 Levels (EQ-5D-5L) as comparators, the authors found good psychometric properties in the 12-question version in the joint replacement population, including excellent responsiveness, although they cautioned that ceiling effects may limit monitoring of postoperative improvement. Robotic-Assisted THA Does robotic-assisted THA improve patient outcomes? That is the question asked by Singh et al. in their study of 1,960 consecutive THAs, including 135 robotic-assisted THAs, 896 navigation-assisted THAs, and 929 THAs with conventionally placed implants28. They reported finding no clinically important differences in patient-reported outcome measures at 1 and 2 years. However, surgical time for the robotics group was significantly longer (p < 0.001) at 119.61 minutes than that for the navigation group (90.35 minutes) or the conventional group (95.35 minutes). For those who do choose to utilize intraoperative robotics, the surgical approach and the patient’s pelvic tilt may affect the accuracy of the technology. Hayashi et al. found that posterior pelvic tilt and an anterior surgical approach were significantly associated with postoperative inaccurate cup positioning in robotic-assisted THA29. Artificial Intelligence In a recent study, Siebelt et al. examined machine learning models for the diagnosis of hip symptoms30. Using a digital questionnaire, the authors found that the Random Forest Model was most accurate; with the addition of Kellgren-Lawrence scores, a Support Vector Machine model was the most accurate. They concluded that machine learning algorithms trained with patient-reported outcome measures and radiographic scores can accurately differentiate diagnoses in patients with hip pain. Current Trends and Debates Lumbar Spinal Fusion or THA First Yang et al. screened 85,595 patients who underwent THA and identified 1,356 patients who underwent THA before lumbar spinal fusion and 2,016 patients who underwent THA after spinal fusion31. The authors found that the patients who underwent THA first had an increased dislocation risk, higher rate of periprosthetic joint infection, surgical site complications, revision, and postoperative opioid use compared with those who underwent THA after lumbar spinal fusion. Vigdorchik et al. have argued that patients undergoing both THA and spinal fusion may benefit from an extended-offset prosthesis32. Using a computed tomography (CT)-based computer software impingement modeling system, the authors assessed 50 consecutive patients with spinal stiffness for osseous or prosthetic impingement during simulated range of motion of virtually implanted prostheses. The stiff spine was identified by examining standing and relaxed-sitting lateral spinopelvic radiographs. Each patient model was run 5 times. Of the 51 dislocations seen, 96% had a standard-offset stem. They reported 5° of additional virtual range of motion before impingement for every 1 mm of offset increase. Sport After THA Patient counseling on return to sport after THA remains variable. In a Level-V study of surgeon opinion, Vu-Han et al. evaluated the return-to-sport recommendations of 300 German orthopaedic surgeons using a questionnaire33. Over 80% of surgeons were in favor of returning to sport after THA, but, with regard to high-impact sport, 51.5% believed that it was appropriate if the patient received adequate training and 34.3% recommended no high-impact sport at all. Postoperative Opioid Use The topic of pain management with opioids remains one of intense international interest. In a study of 507 patients who underwent either THA or TKA, Ruddell et al. evaluated the impact of initial postoperative prescriptions34. The authors noted a dose-dependent relationship between initial outpatient dosing and greater future quantities of opioids consumed. They found that 30% of patients required postoperative opioids between days 31 to 90 and each 1-morphine milligram equivalent (MME) increase in the initial outpatient prescription was associated with a 0.997-MME increase in the quantity filled during the prolonged period. Among the 14% requiring opioids between postoperative days 91 and 150, this increased to 1.678 MME. The authors recommended that providers should attempt to minimize early outpatient opioid utilization. Such a reduction in opioids prescribed after THA is not associated with a decrease in patient satisfaction, according to Bloom et al.35. Using an opioid-sparse protocol published by Feng et al.36, Bloom et al. reported a 73.8% reduction in mean opioids prescribed at discharge, with a mean prescription of 114 ± 156 MME in the final cohort, down from a previous level of 432 ± 298 MME (p < 0.001). They saw no associated decrease in patient satisfaction scores. Perioperative Management Prophylactic Antibiotics In their AAHKS (American Association of Hip and Knee Surgeons) Clinical Research Award paper, Kheir et al. examined whether a 7-day postoperative course of oral antibiotics could reduce the risk of periprosthetic joint infection in patients identified as high-risk37. The study reviewed 3,855 consecutive THAs and TKAs performed between 2011 and 2019. Starting in 2015, high-risk patients were managed with an extended antibiotics protocol commencing after inpatient intravenous antibiotics were completed. High-risk patients with extended antibiotic prophylaxis had a significantly lower rate of periprosthetic joint infection (0.89%) than high-risk patients without extended antibiotic prophylaxis (2.64%). No difference in the infection rate was observed between high-risk patients who received the extended antibiotics and low-risk patients. Intrawound Vancomycin In their recent systematic review of the use of topical vancomycin to prevent periprosthetic joint infection in THA and TKA, Wong et al. called the practice into question38. The authors identified 9 studies, including 3,371 patients who received topical vancomycin and 2,884 patients who did not. The authors found no convincing evidence for the practice. They identified 6 studies in which overall complications could be compared and found no difference in overall complication risks with topical vancomycin, but warned that these studies were underpowered for detecting differences in uncommon complications associated with vancomycin use (e.g., ototoxicity, allergy, and nephrotoxicity). The authors concluded that, without a sufficiently large evidence base reporting on safety-related end points and in the absence of clear evidence of efficacy, topical vancomycin powder should not be used in routine primary THA and TKA. Povidone-Iodine Irrigation Kim et al. questioned the practice of povidone-iodine lavage in a systematic review and meta-analysis of 7 studies with 31,213 THA and TKA cases including 8,861 patients who received povidone-iodine lavage and 22,352 patients who did not39. The authors reported no detected difference in the overall postoperative infection rates between the groups with and without povidone-iodine lavage before wound closure in primary THAs and TKAs and aseptic revision arthroplasties at 3 or 12 months postoperatively in all studies in the subgroup analysis. Anesthesia and Analgesia Surgeons advocating for both spinal analgesia and operating room efficiency may be interested in a recent study by Ritz et al.40. The authors questioned if administration of spinal anesthesia for THA and TKA in the preoperative area, before entering the operating room, was safe and whether it would have positive effects on perioperative efficiency. They reported no adverse events when administering spinal anesthesia preoperatively before entering the operating room, and they recorded shorter anesthesia induction times, shorter operating room recovery times, and shorter post-anesthesia care unit recovery times. Turnover times were longer, negating these gains. Tranexamic Acid (TXA) In a meta-analysis of the use of intravenous TXA and its impact on wound complications, Sukeik et al. identified 25 clinical trials including 1,608 patients41. Although the authors found that TXA use did reduce blood loss and transfusion rates without an increase in thrombotic complications, there was no significant difference in the use of antibiotics or surgical intervention for wound problems. Levack et al. studied TXA use in the setting of periacetabular osteotomy using a placebo-controlled, double-blinded randomized trial42. The authors found that intravenous TXA reduced intraoperative blood loss by 293 mL and the frequency of allogenic transfusion by 73%. Prophylaxis for Thromboembolism Two studies have added to the growing body of data for aspirin prophylaxis for thromboembolism. The first study was a systematic review of the literature that included 45 studies. In that study, Azboy et al. suggested that low-dose aspirin for patients after total joint arthroplasty is not inferior to high-dose aspirin in preventing venous thromboembolism43. The second study was a systematic review and meta-analysis. In that study, Matharu et al. suggested that aspirin taken as venous thromboembolism prophylaxis after THA and TKA did not differ in clinical effectiveness in a significant way from other anticoagulants44. Laboratory Studies To investigate the utility of preoperative laboratory studies, Ondeck et al. queried a national database from 2011 to 2015, identifying 92,093 patients45. The authors found that abnormal preoperative creatinine and sodium levels were associated with the occurrence of all studied adverse outcomes. Sequeira et al. evaluated 98,681 patients with a preoperative diagnosis of iron deficiency anemia46. The authors found that patients with preoperative iron deficiency anemia who underwent THA, when compared with 386,724 matched controls, were at greater risk for experiencing early postoperative complications and had greater utilization of hospital resources, including increased risks of 30-day emergency department visits and 30-day readmission. Iron deficiency anemia was associated with major complications such as increased 1-year rates of periprosthetic joint infection, revision, dislocation, and fracture. In addition, it was significantly associated with an increased 90-day medical complication rate. Compared with the controls, patients with iron deficiency anemia accrued lower hospital reimbursement ($5,509.90 compared with $3,605.59) and higher hospital charges ($27,658.27 compared with $16,709.18). With regard to postoperative laboratory studies, Wu et al. performed a retrospective study of 395 consecutive patients undergoing THA47. The authors sought to evaluate the utility of routine postoperative laboratory tests in an Asian population. The authors identified 6.8% of patients who received medical intervention that was directly related to postoperative abnormal laboratory values. The most frequent abnormalities observed were anemia and hypoalbuminemia, and the intervention rates for patients with abnormal postoperative creatinine, sodium, potassium, and calcium were deemed to be extremely low. Postoperative Rehabilitation Postoperative rehabilitation after THA in the United States is estimated to cost in excess of $180 million per year48. In a recent systematic review and meta-analysis, Saueressig et al. sought to explore the clinical outcomes associated with exercise training before and after THA49. Including 26 randomized clinical trials with 1,004 patients, the authors reported that, compared with usual intervention or no or minimal intervention, postoperative exercise training was not associated with improved self-reported physical function at 4 and 26 weeks postoperatively. Comparing preoperative exercise interventions with the control group revealed no association between exercise training and self-reported physical function at the 12-week and 1-year follow-ups. The authors suggested that routine preoperative exercise training may not be necessary, and recent guidelines have indicated that supervised postoperative training may only be needed in select subgroups, such as those with difficulty with activities of daily living and those with cognitive impairments. Evidence-Based Orthopaedics The editorial staff of JBJS reviewed a large number of recently published studies related to the musculoskeletal system that received a higher Level of Evidence grade. In addition to articles cited already in this update, 4 other articles relevant to hip surgery are appended to this review after the standard bibliography, with a brief commentary about each article to help guide your further reading, in an evidence-based fashion, in this subspecialty area. Evidence-Based Orthopaedics Bergvinsson H, Sundberg M, Flivik G. Polyethylene wear with ceramic and metal femoral heads at 5 years: a randomized controlled trial with radiostereometric analysis. J Arthroplasty. 2020 Dec;35(12):3769-76. Epub 2020 Jun 23. Using radiostereometric analysis, 50 patients with osteoarthritis undergoing THA were randomized to have either a cobalt-chromium femoral head or a ceramic femoral head and were followed at intervals. At the 5-year follow-up, both groups had very low wear rates (<0.01 mm/yr) and no differences in cup migration or clinical outcomes were observed. At a time when THA implants have been increasingly seen as a cost center for orthopaedic practices and hospitals, the age of patients undergoing THA has been decreasing. This has the potential to create conflicting motivations for implant contracting and selection. This study suggested that, at least in terms of wear rates, there was no advantage in choosing one femoral head material over another when the head is mated with a cross-linked polyethylene implant. This may be useful information when choosing implants. Bober K, Kadado A, Charters M, Ayoola A, North T. Pain control after total hip arthroplasty: a randomized controlled trial determining efficacy of fascia iliaca compartment blocks in the immediate postoperative period. J Arthroplasty. 2020 Jun;35(6S):S241-S245. Epub 2020 Feb 14. In this randomized placebo-controlled trial, 122 patients undergoing THA received either a fascia iliaca compartment block or a placebo block and were evaluated for pain and morphine equivalents used during the first 24 hours as well as distanced walked and get-up-and-go testing at the first physical therapy session. No differences were seen between the 2 groups in terms of pain measures, ambulation, or get-up-and-go times. In contrast, 22% of patients receiving the fascia iliaca block demonstrated quadriceps weakness, necessitating a change to their therapy protocol. In a health-care environment that increasingly requires the cost savings realized with total joint arthroplasties performed in patients who are then discharged, on the same day of the surgical procedure, from the hospital either to home or to a non-medical setting with a nurse (at a hotel or a nearby site suite), the decreased quadriceps function demonstrated here may have implications for this intervention’s appropriateness specifically for the ambulatory setting; the lack of demonstrated positive effect in any of the metrics evaluated calls into question the practice in general. The authors’ conclusion that the fascia iliaca block cannot be recommended for patients undergoing THA appears justified and may prove to be useful when counseling patients considering this intervention. Sershon RA, Fillingham YA, Abdel MP, Malkani AL, Schwarzkopf R, Padgett DE, Vail TP, Nam D, Nahhas C, Culvern C, Della Valle CJ; Hip Society Research Group. The optimal dosing regimen for tranexamic acid in revision total hip arthroplasty: a multicenter randomized clinical trial. J Bone Joint Surg Am. 2020 Nov 4;102(21):1883-90. In this multicenter, randomized trial, 4 dosing regimens were compared for safety and efficacy: (1) a single 1-g dose of TXA administered intravenously prior to incision; (2) 1-g intravenous TXA administered prior to incision, followed by 1-g intravenous TXA administered at closure; (3) a combination of 1-g intravenous TXA administered prior to incision and 1-g intraoperative topical TXA; and (4) 3 oral TXA doses totaling 1,950 mg. Assuming that a >1-g/dL difference in hemoglobin reduction was clinically important, equivalence testing showed that all possible pairings were statistically equivalent. There was only 1 venous thromboembolism overall and no differences were found between groups. Although the use of TXA in the management of patients undergoing THA has been notably positive since its widespread adoption, great variability in its administration and dosing has added a level of uncertainty, in part driven by practice site-specific protocols. The authors suggested that a wide range of practice may be appropriate in terms of efficacy and patient safety. Tabori-Jensen S, Mosegaard SB, Hansen TB, Stilling M. Inferior stabilization of cementless compared with cemented dual-mobility cups in elderly osteoarthrosis patients: a randomized controlled radiostereometry study on 60 patients with 2 years’ follow-up. Acta Orthop. 2020 Jun;91(3):246-53. Epub 2020 Feb 6. In this patient-blinded, randomized trial of 60 patients undergoing THA for osteoarthritis, Tabori-Jensen et al. used radiostereometry to assess acetabular fixation in elderly patients. The authors found that cemented acetabular components ceased migration at 3 months and cementless implants in patients with low bone mineral density had not stabilized after 2 years. These data provide insight into the natural history of cementless acetabular components in the elderly population and may be of use in implant selection in this population. Taken with data on the increased periprosthetic femoral fracture risk in the elderly patient managed with a cementless device, this study may indicate that a role remains in modern practice for the THA performed with cemented components.